Paints and coatings play an important role in preserving, protecting and beautifying the objects to which they are applied. Architectural paints are used to decorate and extend the service life of the interior and exterior surfaces of residential and commercial buildings.
“Hollow latexes” (i.e., voided latex particles) which are non-film-forming have been developed for use as opacifiers in paints and other coatings. As such, they are typically used as full or partial replacements for other opacifying agents such as titanium dioxide.
Known processes for preparing hollow polymer particles including a separate swelling step that occurs after polymerization of the core and shell layers or in between formation of shell layers requires specific timing of those steps that are difficult to carry out on a commercial plant scale. If the timing of these steps is not ideal, the final geometric structures of the particles are compromised. Timing of these steps may result in shell thickness, void diameter, particle size, and particle morphology (such as the formation of penetrating pores) that result in undesirable product performance.